Add Clock page with live DB time and TimeApiClient service

Introduced a new Clock page that displays and updates the current database server time every second by calling a backend API. Added the TimeApiClient service to handle API requests for the server time. Registered TimeApiClient in Program.cs and updated the navigation menu to include a link to the new Clock page. Includes error handling and custom UI styling for the clock display.

DbFirst.API/Controllers/TimeController.cs

@@ -0,0 +1,28 @@
+using DbFirst.Application.Time.Commands;
+using DbFirst.Domain.Entities;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+
+namespace DbFirst.API.Controllers;
+
+[ApiController]
+[Route("api/[controller]")]
+public class TimeController : ControllerBase
+{
+    private readonly IMediator _mediator;
+
+    public TimeController(IMediator mediator)
+    {
+        _mediator = mediator;
+    }
+
+    [HttpPost]
+    public async Task<ActionResult<TimeRecord>> InsertAndGetLast(CancellationToken cancellationToken)
+    {
+        var result = await _mediator.Send(new InsertTimeCommand(), cancellationToken);
+        if (result == null)
+            return NotFound();
+
+        return Ok(result);
+    }
+}

DbFirst.API/Program.cs

@@ -54,6 +54,7 @@ builder.Services.AddApplication();
 builder.Services.AddScoped<ICatalogRepository, CatalogRepository>();
 builder.Services.AddScoped<IMassDataRepository, MassDataRepository>();
 builder.Services.AddScoped<ILayoutRepository, LayoutRepository>();
+builder.Services.AddScoped<ITimeRepository, TimeRepository>();
 
 builder.Services.AddDevExpressControls();
 builder.Services.AddSignalR();

DbFirst.Application/Repositories/ITimeRepository.cs

@@ -0,0 +1,9 @@
+using DbFirst.Domain.Entities;
+
+namespace DbFirst.Application.Repositories;
+
+public interface ITimeRepository
+{
+    Task InsertAsync(CancellationToken cancellationToken = default);
+    Task<TimeRecord?> GetLastAsync(CancellationToken cancellationToken = default);
+}

DbFirst.Application/Time/Commands/InsertTimeCommand.cs

@@ -0,0 +1,6 @@
+using DbFirst.Domain.Entities;
+using MediatR;
+
+namespace DbFirst.Application.Time.Commands;
+
+public record InsertTimeCommand : IRequest<TimeRecord?>;

DbFirst.Application/Time/Commands/InsertTimeHandler.cs

@@ -0,0 +1,21 @@
+using DbFirst.Application.Repositories;
+using DbFirst.Domain.Entities;
+using MediatR;
+
+namespace DbFirst.Application.Time.Commands;
+
+public class InsertTimeHandler : IRequestHandler<InsertTimeCommand, TimeRecord?>
+{
+    private readonly ITimeRepository _repository;
+
+    public InsertTimeHandler(ITimeRepository repository)
+    {
+        _repository = repository;
+    }
+
+    public async Task<TimeRecord?> Handle(InsertTimeCommand request, CancellationToken cancellationToken)
+    {
+        await _repository.InsertAsync(cancellationToken);
+        return await _repository.GetLastAsync(cancellationToken);
+    }
+}

DbFirst.BlazorWebApp/Components/App.razor

@@ -25,6 +25,7 @@
     <link rel="stylesheet" href="app.css" />
     <link rel="stylesheet" href="DbFirst.BlazorWebApp.styles.css" />
     <link rel="icon" type="image/png" href="favicon.png" />
+    <script src="js/size-manager.js"></script>
     <HeadOutlet />
 </head>
 

DbFirst.BlazorWebApp/Components/CatalogsGrid.razor

@@ -1,60 +1,5 @@
-@using System.Text.Json
-@using Microsoft.AspNetCore.Components
-@using Microsoft.AspNetCore.Components.Rendering
-@using Microsoft.AspNetCore.Components.Forms
-@using DevExpress.Blazor
-@using DevExpress.Data.Filtering
 @inject CatalogApiClient Api
-@inject LayoutApiClient LayoutApi
-@inject IJSRuntime JsRuntime
-
-<style>
-    .action-panel { margin-bottom: 16px; }
-    .grid-section { margin-top: 12px; }
-    .catalog-edit-popup {
-        min-width: 720px;
-    }
-    .band-editor {
-        display: grid;
-        gap: 12px;
-        margin-bottom: 16px;
-    }
-    .band-controls {
-        display: flex;
-        flex-wrap: wrap;
-        gap: 8px;
-        align-items: center;
-    }
-    .band-row {
-        display: flex;
-        gap: 8px;
-        align-items: center;
-    }
-    .band-columns {
-        max-width: 720px;
-    }
-    .filter-row-cell {
-        display: flex;
-        align-items: center;
-        gap: 4px;
-        flex-wrap: wrap;
-    }
-    .filter-operator {
-        width: 52px;
-        min-width: 52px;
-        flex: 0 0 52px;
-    }
-    .filter-value {
-        min-width: 160px;
-        flex: 1 1 160px;
-    }
-    .loading-container {
-        min-height: 160px;
-        display: flex;
-        align-items: center;
-        justify-content: center;
-    }
-</style>
+@inject BandLayoutService BandLayoutService
 
 @if (!string.IsNullOrWhiteSpace(errorMessage))
 {
@@ -80,39 +25,49 @@ else if (items.Count == 0)
 else
 {
     <div class="band-editor">
-        <div class="band-controls">
-            <DxButton Text="Band hinzufügen" Click="AddBand" />
-            <DxButton Text="Layout speichern" Click="SaveLayoutAsync" Enabled="@CanSaveBandLayout" />
-            <DxButton Text="Band-Layout zurücksetzen" Click="ResetBandLayoutAsync" />
-        </div>
-        @foreach (var band in bandLayout.Bands)
+        <button class="band-editor-toggle" @onclick="() => bandEditorExpanded = !bandEditorExpanded">
+            <span class="band-editor-toggle-icon @(bandEditorExpanded ? "expanded" : "")">&#9658;</span>
+            <span>Layout</span>
+        </button>
+        @if (bandEditorExpanded)
         {
-            <div class="band-row">
-                <DxTextBox Text="@band.Caption" TextChanged="@(value => UpdateBandCaption(band, value))" />
-                <DxButton Text="Entfernen" Click="@(() => RemoveBand(band))" />
+            <div class="band-editor-body">
+                <div class="band-controls">
+                    <DxButton Text="Band hinzufügen" Click="AddBand" />
+                    <DxButton Text="Layout speichern" Click="SaveLayoutAsync" Enabled="@CanSaveBandLayout" />
+                    <DxButton Text="Layout zurücksetzen" Click="ResetLayoutAsync" />
+                </div>
+                @foreach (var band in bandLayout.Bands)
+                {
+                    <div class="band-row">
+                        <DxTextBox Text="@band.Caption" TextChanged="@(value => UpdateBandCaption(band, value))" />
+                        <DxButton Text="Entfernen" Click="@(() => RemoveBand(band))" />
+                    </div>
+                }
+                <DxFormLayout CssClass="band-columns" ColCount="2">
+                    @foreach (var column in columnDefinitions)
+                    {
+                        <DxFormLayoutItem Caption="@column.Caption">
+                            <DxComboBox Data="@bandOptions"
+                                        TData="BandOption"
+                                        TValue="string"
+                                        TextFieldName="Caption"
+                                        ValueFieldName="Id"
+                                        Value="@GetColumnBand(column.FieldName)"
+                                        ValueChanged="@(value => UpdateColumnBand(column.FieldName, value))"
+                                        Width="100%" />
+                        </DxFormLayoutItem>
+                    }
+                </DxFormLayout>
             </div>
         }
-        <DxFormLayout CssClass="band-columns" ColCount="2">
-            @foreach (var column in columnDefinitions)
-            {
-                <DxFormLayoutItem Caption="@column.Caption">
-                    <DxComboBox Data="@bandOptions"
-                                TData="BandOption"
-                                TValue="string"
-                                TextFieldName="Caption"
-                                ValueFieldName="Id"
-                                Value="@GetColumnBand(column.FieldName)"
-                                ValueChanged="@(value => UpdateColumnBand(column.FieldName, value))"
-                                Width="100%" />
-                </DxFormLayoutItem>
-            }
-        </DxFormLayout>
     </div>
 
     <div class="grid-section">
         <DxGrid Data="@items"
                 TItem="CatalogReadDto"
                 KeyFieldName="@nameof(CatalogReadDto.Guid)"
+                SizeMode="@_sizeMode"
                 ShowGroupPanel="true"
                 ShowGroupedColumns="true"
                 AllowGroup="true"
@@ -131,11 +86,32 @@ else
                 FocusedRowEnabled="true"
                 @bind-FocusedRowKey="focusedRowKey"
                 @ref="gridRef">
+            <ToolbarTemplate>
+                <DxToolbar>
+                    <DxToolbarItem Alignment="ToolbarItemAlignment.Right">
+                        <Template Context="_">
+                            <DxDropDownButton Text="@FormatSizeText(_sizeMode)"
+                                              RenderStyle="ButtonRenderStyle.Secondary"
+                                              RenderStyleMode="ButtonRenderStyleMode.Text"
+                                              ItemClick="OnSizeChange">
+                                <Items>
+                                    @foreach (var size in _sizeModes)
+                                    {
+                                        <DxDropDownButtonItem Text="@FormatSizeText(size)" Id="@size.ToString()" />
+                                    }
+                                </Items>
+                            </DxDropDownButton>
+                        </Template>
+                    </DxToolbarItem>
+                </DxToolbar>
+            </ToolbarTemplate>
             <Columns>
                 @RenderColumns()
             </Columns>
             <EditFormTemplate Context="editFormContext">
-                @{ SetEditContext(editFormContext.EditContext); var editModel = (CatalogEditModel)editFormContext.EditModel; SetPopupHeaderText(editModel.IsNew); }
+                @{
+                    SetEditContext(editFormContext.EditContext); var editModel = (CatalogEditModel)editFormContext.EditModel; SetPopupHeaderText(editModel.IsNew);
+                }
                 <DxFormLayout ColCount="2">
                     <DxFormLayoutItem Caption="Titel">
                         <DxTextBox @bind-Text="editModel.CatTitle" Width="100%" />
@@ -177,13 +153,14 @@ else
     private string popupHeaderText = "Edit";
     private const string LayoutType = "GRID_BANDS";
     private const string LayoutKey = "CatalogsGrid";
-    private const string LayoutUserStorageKey = "layoutUser";
     private string? layoutUser;
     private BandLayout bandLayout = new();
     private Dictionary<string, string> columnBandAssignments = new();
     private List<BandOption> bandOptions = new();
     private Dictionary<string, ColumnDefinition> columnLookup = new();
-    private readonly JsonSerializerOptions jsonOptions = new(JsonSerializerDefaults.Web);
+    private bool gridLayoutApplied;
+    private bool bandEditorExpanded;
+
     private List<ColumnDefinition> columnDefinitions = new()
     {
         new() { FieldName = nameof(CatalogReadDto.Guid), Caption = "Id", Width = "140px", FilterType = ColumnFilterType.Text },
@@ -202,13 +179,32 @@ else
     };
 
     private bool CanSaveBandLayout => !string.IsNullOrWhiteSpace(layoutUser);
-    private bool gridLayoutApplied;
+
+    private SizeMode _sizeMode = SizeMode.Medium;
+    private static readonly List<SizeMode> _sizeModes = Enum.GetValues<SizeMode>().ToList();
+
+    private string FormatSizeText(SizeMode size) => size switch
+    {
+        SizeMode.Small => "Klein",
+        SizeMode.Medium => "Mittel",
+        SizeMode.Large => "Groß",
+        _ => size.ToString()
+    };
+
+    private void OnSizeChange(DropDownButtonItemClickEventArgs args)
+    {
+        _sizeMode = Enum.Parse<SizeMode>(args.ItemInfo.Id);
+    }
 
     protected override async Task OnInitializedAsync()
     {
-        columnLookup = columnDefinitions.ToDictionary(column => column.FieldName, StringComparer.OrdinalIgnoreCase);
-        await EnsureLayoutUserAsync();
-        await LoadBandLayoutAsync();
+        columnLookup = columnDefinitions.ToDictionary(c => c.FieldName, StringComparer.OrdinalIgnoreCase);
+        layoutUser = await BandLayoutService.EnsureLayoutUserAsync();
+        bandLayout = await BandLayoutService.LoadBandLayoutAsync(LayoutType, LayoutKey, layoutUser, columnLookup);
+        columnBandAssignments = BandLayoutService.BuildAssignmentsFromLayout(bandLayout);
+        ApplyColumnLayoutFromStorage();
+        _sizeMode = bandLayout.SizeMode;
+        UpdateBandOptions();
         await LoadCatalogs();
     }
 
@@ -222,71 +218,6 @@ else
         }
     }
 
-    private void SetEditContext(EditContext context)
-    {
-        if (editContext == context)
-        {
-            return;
-        }
-
-        if (editContext != null)
-        {
-            editContext.OnFieldChanged -= OnEditFieldChanged;
-        }
-
-        editContext = context;
-        validationMessageStore = new ValidationMessageStore(editContext);
-        editContext.OnFieldChanged += OnEditFieldChanged;
-    }
-
-    private void OnEditFieldChanged(object? sender, FieldChangedEventArgs e)
-    {
-        if (validationMessageStore == null || editContext == null)
-        {
-            return;
-        }
-
-        if (e.FieldIdentifier.FieldName == nameof(CatalogEditModel.UpdateProcedure))
-        {
-            validationMessageStore.Clear();
-            editContext.NotifyValidationStateChanged();
-            return;
-        }
-
-        if (e.FieldIdentifier.FieldName == nameof(CatalogEditModel.CatTitle))
-        {
-            var field = new FieldIdentifier(editContext.Model, nameof(CatalogEditModel.CatTitle));
-            validationMessageStore.Clear(field);
-            editContext.NotifyValidationStateChanged();
-        }
-    }
-
-    private void SetPopupHeaderText(bool isNew)
-    {
-        popupHeaderText = isNew ? "Neu" : "Edit";
-    }
-
-    private void OnCustomizeEditModel(GridCustomizeEditModelEventArgs e)
-    {
-        popupHeaderText = e.IsNew ? "Neu" : "Edit";
-        if (e.IsNew)
-        {
-            e.EditModel = new CatalogEditModel { IsNew = true };
-            return;
-        }
-
-        var item = (CatalogReadDto)e.DataItem;
-        e.EditModel = new CatalogEditModel
-        {
-            Guid = item.Guid,
-            CatTitle = item.CatTitle,
-            CatString = item.CatString,
-            UpdateProcedure = 0,
-            OriginalCatTitle = item.CatTitle,
-            IsNew = false
-        };
-    }
-
     private async Task LoadCatalogs()
     {
         isLoading = true;
@@ -307,11 +238,229 @@ else
         }
     }
 
+    private async Task SaveLayoutAsync()
+    {
+        if (string.IsNullOrWhiteSpace(layoutUser))
+            return;
+
+        try
+        {
+            CaptureColumnLayoutFromGrid();
+            await BandLayoutService.SaveBandLayoutAsync(LayoutType, LayoutKey, layoutUser, bandLayout);
+            infoMessage = "Layout gespeichert.";
+            errorMessage = null;
+        }
+        catch (Exception ex)
+        {
+            errorMessage = $"Layout konnte nicht gespeichert werden: {ex.Message}";
+        }
+    }
+
+    private async Task ResetLayoutAsync()
+    {
+        if (string.IsNullOrWhiteSpace(layoutUser))
+            return;
+
+        await BandLayoutService.ResetBandLayoutAsync(LayoutType, LayoutKey, layoutUser);
+
+        bandLayout = new BandLayout();
+        columnBandAssignments.Clear();
+        UpdateBandOptions();
+
+        foreach (var column in columnDefinitions)
+            column.Width = null;
+        columnLookup = columnDefinitions.ToDictionary(c => c.FieldName, StringComparer.OrdinalIgnoreCase);
+
+        _sizeMode = SizeMode.Medium;
+
+        if (gridRef != null)
+            gridRef.LoadLayout(new GridPersistentLayout());
+        gridLayoutApplied = false;
+
+        infoMessage = "Layout zurückgesetzt.";
+        errorMessage = null;
+    }
+
+    private void CaptureColumnLayoutFromGrid()
+    {
+        if (gridRef == null)
+            return;
+
+        var layout = gridRef.SaveLayout();
+        bandLayout.GridLayout = layout;
+        bandLayout.SizeMode = _sizeMode;
+
+        var orderedColumns = layout.Columns
+            .Where(c => !string.IsNullOrWhiteSpace(c.FieldName))
+            .OrderBy(c => c.VisibleIndex)
+            .ToList();
+
+        bandLayout.ColumnOrder = orderedColumns.Select(c => c.FieldName).ToList();
+        bandLayout.ColumnWidths = orderedColumns
+            .Where(c => !string.IsNullOrWhiteSpace(c.Width))
+            .ToDictionary(c => c.FieldName, c => c.Width, StringComparer.OrdinalIgnoreCase);
+    }
+
+    private void ApplyColumnLayoutFromStorage()
+    {
+        foreach (var column in columnDefinitions)
+        {
+            if (bandLayout.ColumnWidths.TryGetValue(column.FieldName, out var width) && !string.IsNullOrWhiteSpace(width))
+                column.Width = width;
+        }
+        columnLookup = columnDefinitions.ToDictionary(c => c.FieldName, StringComparer.OrdinalIgnoreCase);
+    }
+
+    private void AddBand()
+    {
+        bandLayout.Bands.Add(new BandDefinition { Id = Guid.NewGuid().ToString("N"), Caption = "Band" });
+        UpdateBandOptions();
+    }
+
+    private void RemoveBand(BandDefinition band)
+    {
+        bandLayout.Bands.Remove(band);
+        foreach (var key in columnBandAssignments.Where(p => p.Value == band.Id).Select(p => p.Key).ToList())
+            columnBandAssignments.Remove(key);
+        UpdateBandOptions();
+        SyncBandsFromAssignments();
+    }
+
+    private void UpdateBandCaption(BandDefinition band, string value)
+    {
+        band.Caption = value;
+        UpdateBandOptions();
+    }
+
+    private void UpdateColumnBand(string fieldName, string? bandId)
+    {
+        if (string.IsNullOrWhiteSpace(bandId))
+            columnBandAssignments.Remove(fieldName);
+        else
+            columnBandAssignments[fieldName] = bandId;
+        SyncBandsFromAssignments();
+    }
+
+    private string GetColumnBand(string fieldName)
+        => columnBandAssignments.TryGetValue(fieldName, out var bandId) ? bandId : string.Empty;
+
+    private void SyncBandsFromAssignments()
+    {
+        foreach (var band in bandLayout.Bands)
+        {
+            band.Columns = columnDefinitions
+                .Where(c => columnBandAssignments.TryGetValue(c.FieldName, out var id) && id == band.Id)
+                .Select(c => c.FieldName)
+                .ToList();
+        }
+        StateHasChanged();
+    }
+
+    private void UpdateBandOptions()
+    {
+        bandOptions = new List<BandOption> { new() { Id = string.Empty, Caption = "Ohne Band" } };
+        bandOptions.AddRange(bandLayout.Bands.Select(b => new BandOption { Id = b.Id, Caption = b.Caption }));
+    }
+
+    private RenderFragment RenderColumns() => builder =>
+    {
+        var seq = 0;
+        builder.OpenComponent<DxGridCommandColumn>(seq++);
+        builder.AddAttribute(seq++, "Width", "120px");
+        builder.CloseComponent();
+
+        var grouped = bandLayout.Bands.SelectMany(b => b.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
+        foreach (var column in columnDefinitions.Where(c => !grouped.Contains(c.FieldName)))
+            BuildDataColumn(builder, ref seq, column);
+
+        foreach (var band in bandLayout.Bands)
+        {
+            if (band.Columns.Count == 0) continue;
+
+            builder.OpenComponent<DxGridBandColumn>(seq++);
+            builder.AddAttribute(seq++, "Caption", band.Caption);
+            builder.AddAttribute(seq++, "Columns", (RenderFragment)(bandBuilder =>
+            {
+                var bandSeq = 0;
+                foreach (var columnName in band.Columns)
+                {
+                    if (columnLookup.TryGetValue(columnName, out var column))
+                        BuildDataColumn(bandBuilder, ref bandSeq, column);
+                }
+            }));
+            builder.CloseComponent();
+        }
+    };
+
+    private void BuildDataColumn(RenderTreeBuilder builder, ref int seq, ColumnDefinition column)
+    {
+        builder.OpenComponent<DxGridDataColumn>(seq++);
+        builder.AddAttribute(seq++, "FieldName", column.FieldName);
+        builder.AddAttribute(seq++, "Caption", column.Caption);
+        if (!string.IsNullOrWhiteSpace(column.Width))
+            builder.AddAttribute(seq++, "Width", column.Width);
+        if (!string.IsNullOrWhiteSpace(column.DisplayFormat))
+            builder.AddAttribute(seq++, "DisplayFormat", column.DisplayFormat);
+        if (column.ReadOnly)
+            builder.AddAttribute(seq++, "ReadOnly", true);
+        builder.CloseComponent();
+    }
+
+    private void SetEditContext(EditContext context)
+    {
+        if (editContext == context) return;
+        if (editContext != null)
+            editContext.OnFieldChanged -= OnEditFieldChanged;
+        editContext = context;
+        validationMessageStore = new ValidationMessageStore(editContext);
+        editContext.OnFieldChanged += OnEditFieldChanged;
+    }
+
+    private void OnEditFieldChanged(object? sender, FieldChangedEventArgs e)
+    {
+        if (validationMessageStore == null || editContext == null) return;
+
+        if (e.FieldIdentifier.FieldName == nameof(CatalogEditModel.UpdateProcedure))
+        {
+            validationMessageStore.Clear();
+            editContext.NotifyValidationStateChanged();
+            return;
+        }
+
+        if (e.FieldIdentifier.FieldName == nameof(CatalogEditModel.CatTitle))
+        {
+            validationMessageStore.Clear(new FieldIdentifier(editContext.Model, nameof(CatalogEditModel.CatTitle)));
+            editContext.NotifyValidationStateChanged();
+        }
+    }
+
+    private void SetPopupHeaderText(bool isNew) => popupHeaderText = isNew ? "Neu" : "Edit";
+
+    private void OnCustomizeEditModel(GridCustomizeEditModelEventArgs e)
+    {
+        popupHeaderText = e.IsNew ? "Neu" : "Edit";
+        if (e.IsNew)
+        {
+            e.EditModel = new CatalogEditModel { IsNew = true };
+            return;
+        }
+
+        var item = (CatalogReadDto)e.DataItem;
+        e.EditModel = new CatalogEditModel
+        {
+            Guid = item.Guid,
+            CatTitle = item.CatTitle,
+            CatString = item.CatString,
+            UpdateProcedure = 0,
+            OriginalCatTitle = item.CatTitle,
+            IsNew = false
+        };
+    }
+
     private async Task OnEditModelSaving(GridEditModelSavingEventArgs e)
     {
         errorMessage = null;
         infoMessage = null;
-
         validationMessageStore?.Clear();
         editContext?.NotifyValidationStateChanged();
 
@@ -337,18 +486,12 @@ else
                 if (!created.Success || created.Value == null)
                 {
                     if (!string.IsNullOrWhiteSpace(created.Error))
-                    {
                         AddValidationError(editModel, nameof(CatalogEditModel.CatTitle), created.Error);
-                    }
                     else
-                    {
                         errorMessage = "Anlegen fehlgeschlagen.";
-                    }
-
                     e.Cancel = true;
                     return;
                 }
-
                 infoMessage = "Katalog angelegt.";
                 focusedRowKey = created.Value.Guid;
             }
@@ -361,7 +504,6 @@ else
                     e.Cancel = true;
                     return;
                 }
-
                 infoMessage = "Katalog aktualisiert.";
                 focusedRowKey = editModel.Guid;
             }
@@ -377,30 +519,20 @@ else
 
     private void AddValidationError(CatalogEditModel editModel, string fieldName, string message)
     {
-        if (editContext == null || validationMessageStore == null)
-        {
-            return;
-        }
-
-        var field = new FieldIdentifier(editModel, fieldName);
-        validationMessageStore.Add(field, message);
+        if (editContext == null || validationMessageStore == null) return;
+        validationMessageStore.Add(new FieldIdentifier(editModel, fieldName), message);
         editContext.NotifyValidationStateChanged();
     }
 
     private bool ValidateEditModel(CatalogEditModel editModel, bool isNew)
     {
-        if (isNew)
-        {
-            return true;
-        }
-
+        if (isNew) return true;
         if (editModel.UpdateProcedure == 0 &&
             !string.Equals(editModel.CatTitle, editModel.OriginalCatTitle, StringComparison.OrdinalIgnoreCase))
         {
             AddValidationError(editModel, nameof(CatalogEditModel.CatTitle), "Titel kann nicht geändert werden.");
             return false;
         }
-
         return true;
     }
 
@@ -408,9 +540,7 @@ else
     {
         errorMessage = null;
         infoMessage = null;
-
         var item = (CatalogReadDto)e.DataItem;
-
         try
         {
             var deleted = await Api.DeleteAsync(item.Guid);
@@ -420,7 +550,6 @@ else
                 e.Cancel = true;
                 return;
             }
-
             infoMessage = "Katalog gelöscht.";
             await LoadCatalogs();
         }
@@ -431,323 +560,6 @@ else
         }
     }
 
-    private async Task EnsureLayoutUserAsync()
-    {
-        layoutUser = await JsRuntime.InvokeAsync<string?>("localStorage.getItem", LayoutUserStorageKey);
-        if (string.IsNullOrWhiteSpace(layoutUser))
-        {
-            layoutUser = Guid.NewGuid().ToString("N");
-            await JsRuntime.InvokeVoidAsync("localStorage.setItem", LayoutUserStorageKey, layoutUser);
-        }
-    }
-
-    private async Task SaveLayoutAsync()
-    {
-        if (string.IsNullOrWhiteSpace(layoutUser))
-        {
-            return;
-        }
-
-        try
-        {
-            CaptureColumnLayoutFromGrid();
-
-            var layoutData = JsonSerializer.Serialize(bandLayout, jsonOptions);
-            await LayoutApi.UpsertAsync(new LayoutDto
-            {
-                LayoutType = LayoutType,
-                LayoutKey = LayoutKey,
-                UserName = layoutUser,
-                LayoutData = layoutData
-            });
-            infoMessage = "Layout gespeichert.";
-            errorMessage = null;
-        }
-        catch (Exception ex)
-        {
-            errorMessage = $"Layout konnte nicht gespeichert werden: {ex.Message}";
-        }
-    }
-
-    private void CaptureColumnLayoutFromGrid()
-    {
-        if (gridRef == null)
-        {
-            return;
-        }
-
-        var layout = gridRef.SaveLayout();
-        bandLayout.GridLayout = layout;
-
-        var orderedColumns = layout.Columns
-            .Where(column => !string.IsNullOrWhiteSpace(column.FieldName))
-            .OrderBy(column => column.VisibleIndex)
-            .ToList();
-
-        bandLayout.ColumnOrder = orderedColumns
-            .Select(column => column.FieldName)
-            .ToList();
-
-        bandLayout.ColumnWidths = orderedColumns
-            .Where(column => !string.IsNullOrWhiteSpace(column.Width))
-            .ToDictionary(column => column.FieldName, column => column.Width, StringComparer.OrdinalIgnoreCase);
-    }
-
-    private async Task LoadBandLayoutAsync()
-    {
-        if (string.IsNullOrWhiteSpace(layoutUser))
-        {
-            bandLayout = new BandLayout();
-            UpdateBandOptions();
-            return;
-        }
-
-        var stored = await LayoutApi.GetAsync(LayoutType, LayoutKey, layoutUser);
-        if (stored != null && !string.IsNullOrWhiteSpace(stored.LayoutData))
-        {
-            var parsed = JsonSerializer.Deserialize<BandLayout>(stored.LayoutData, jsonOptions);
-            bandLayout = NormalizeBandLayout(parsed);
-        }
-        else
-        {
-            bandLayout = new BandLayout();
-        }
-
-        columnBandAssignments = BuildAssignmentsFromLayout(bandLayout);
-        ApplyColumnLayoutFromStorage();
-        UpdateBandOptions();
-    }
-
-    private async Task ResetBandLayoutAsync()
-    {
-        if (string.IsNullOrWhiteSpace(layoutUser))
-        {
-            return;
-        }
-
-        await LayoutApi.DeleteAsync(LayoutType, LayoutKey, layoutUser);
-        bandLayout = new BandLayout();
-        columnBandAssignments.Clear();
-        UpdateBandOptions();
-        infoMessage = "Band-Layout zurückgesetzt.";
-    }
-
-    private void ApplyColumnLayoutFromStorage()
-    {
-        foreach (var column in columnDefinitions)
-        {
-            if (bandLayout.ColumnWidths.TryGetValue(column.FieldName, out var width) && !string.IsNullOrWhiteSpace(width))
-            {
-                column.Width = width;
-            }
-        }
-
-        columnLookup = columnDefinitions.ToDictionary(column => column.FieldName, StringComparer.OrdinalIgnoreCase);
-    }
-
-    private void AddBand()
-    {
-        bandLayout.Bands.Add(new BandDefinition
-        {
-            Id = Guid.NewGuid().ToString("N"),
-            Caption = "Band"
-        });
-        UpdateBandOptions();
-    }
-
-    private void RemoveBand(BandDefinition band)
-    {
-        bandLayout.Bands.Remove(band);
-        var removedColumns = columnBandAssignments.Where(pair => pair.Value == band.Id)
-            .Select(pair => pair.Key)
-            .ToList();
-        foreach (var column in removedColumns)
-        {
-            columnBandAssignments.Remove(column);
-        }
-        UpdateBandOptions();
-        SyncBandsFromAssignments();
-    }
-
-    private void UpdateBandCaption(BandDefinition band, string value)
-    {
-        band.Caption = value;
-        UpdateBandOptions();
-    }
-
-    private void UpdateColumnBand(string fieldName, string? bandId)
-    {
-        if (string.IsNullOrWhiteSpace(bandId))
-        {
-            columnBandAssignments.Remove(fieldName);
-        }
-        else
-        {
-            columnBandAssignments[fieldName] = bandId;
-        }
-
-        SyncBandsFromAssignments();
-    }
-
-    private string GetColumnBand(string fieldName)
-    {
-        return columnBandAssignments.TryGetValue(fieldName, out var bandId) ? bandId : string.Empty;
-    }
-
-    private void SyncBandsFromAssignments()
-    {
-        foreach (var band in bandLayout.Bands)
-        {
-            band.Columns = columnDefinitions
-                .Where(column => columnBandAssignments.TryGetValue(column.FieldName, out var bandId) && bandId == band.Id)
-                .Select(column => column.FieldName)
-                .ToList();
-        }
-
-        StateHasChanged();
-    }
-
-    private void UpdateBandOptions()
-    {
-        bandOptions = new List<BandOption> { new() { Id = string.Empty, Caption = "Ohne Band" } };
-        bandOptions.AddRange(bandLayout.Bands.Select(band => new BandOption { Id = band.Id, Caption = band.Caption }));
-    }
-
-    private BandLayout NormalizeBandLayout(BandLayout? layout)
-    {
-        layout ??= new BandLayout();
-        layout.Bands ??= new List<BandDefinition>();
-        layout.ColumnOrder ??= new List<string>();
-        layout.ColumnWidths ??= new Dictionary<string, string?>(StringComparer.OrdinalIgnoreCase);
-        foreach (var band in layout.Bands)
-        {
-            if (string.IsNullOrWhiteSpace(band.Id))
-            {
-                band.Id = Guid.NewGuid().ToString("N");
-            }
-
-            if (string.IsNullOrWhiteSpace(band.Caption))
-            {
-                band.Caption = "Band";
-            }
-
-            band.Columns = band.Columns?.Where(columnLookup.ContainsKey).ToList() ?? new List<string>();
-        }
-
-        return layout;
-    }
-
-    private Dictionary<string, string> BuildAssignmentsFromLayout(BandLayout layout)
-    {
-        var assignments = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-        foreach (var band in layout.Bands)
-        {
-            foreach (var column in band.Columns)
-            {
-                assignments[column] = band.Id;
-            }
-        }
-
-        return assignments;
-    }
-
-    private RenderFragment RenderColumns() => builder =>
-    {
-        var seq = 0;
-        builder.OpenComponent<DxGridCommandColumn>(seq++);
-        builder.AddAttribute(seq++, "Width", "120px");
-        builder.CloseComponent();
-
-        var grouped = bandLayout.Bands.SelectMany(band => band.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
-        foreach (var column in columnDefinitions.Where(column => !grouped.Contains(column.FieldName)))
-        {
-            BuildDataColumn(builder, ref seq, column);
-        }
-
-        foreach (var band in bandLayout.Bands)
-        {
-            if (band.Columns.Count == 0)
-            {
-                continue;
-            }
-
-            builder.OpenComponent<DxGridBandColumn>(seq++);
-            builder.AddAttribute(seq++, "Caption", band.Caption);
-            builder.AddAttribute(seq++, "Columns", (RenderFragment)(bandBuilder =>
-            {
-                var bandSeq = 0;
-                foreach (var columnName in band.Columns)
-                {
-                    if (columnLookup.TryGetValue(columnName, out var column))
-                    {
-                        BuildDataColumn(bandBuilder, ref bandSeq, column);
-                    }
-                }
-            }));
-            builder.CloseComponent();
-        }
-    };
-
-    private void BuildDataColumn(RenderTreeBuilder builder, ref int seq, ColumnDefinition column)
-    {
-        builder.OpenComponent<DxGridDataColumn>(seq++);
-        builder.AddAttribute(seq++, "FieldName", column.FieldName);
-        builder.AddAttribute(seq++, "Caption", column.Caption);
-        if (!string.IsNullOrWhiteSpace(column.Width))
-        {
-            builder.AddAttribute(seq++, "Width", column.Width);
-        }
-
-        if (!string.IsNullOrWhiteSpace(column.DisplayFormat))
-        {
-            builder.AddAttribute(seq++, "DisplayFormat", column.DisplayFormat);
-        }
-
-        if (column.ReadOnly)
-        {
-            builder.AddAttribute(seq++, "ReadOnly", true);
-        }
-
-        builder.CloseComponent();
-    }
-
-    private sealed class BandLayout
-    {
-        public List<BandDefinition> Bands { get; set; } = new();
-        public List<string> ColumnOrder { get; set; } = new();
-        public Dictionary<string, string?> ColumnWidths { get; set; } = new(StringComparer.OrdinalIgnoreCase);
-        public GridPersistentLayout? GridLayout { get; set; }
-    }
-
-    private sealed class BandDefinition
-    {
-        public string Id { get; set; } = string.Empty;
-        public string Caption { get; set; } = string.Empty;
-        public List<string> Columns { get; set; } = new();
-    }
-
-    private sealed class BandOption
-    {
-        public string Id { get; set; } = string.Empty;
-        public string Caption { get; set; } = string.Empty;
-    }
-
-    private sealed class ColumnDefinition
-    {
-        public string FieldName { get; init; } = string.Empty;
-        public string Caption { get; init; } = string.Empty;
-        public string? Width { get; set; }
-        public string? DisplayFormat { get; init; }
-        public bool ReadOnly { get; init; }
-        public ColumnFilterType FilterType { get; init; }
-    }
-
-    private enum ColumnFilterType
-    {
-        Text,
-        Date
-    }
-
     private sealed class CatalogEditModel
     {
         public int Guid { get; set; }
@@ -763,10 +575,4 @@ else
         public int Value { get; set; }
         public string Text { get; set; } = string.Empty;
     }
-
-    private sealed class FilterOperatorOption
-    {
-        public string Value { get; set; } = string.Empty;
-        public string Text { get; set; } = string.Empty;
-    }
-}
+}

DbFirst.BlazorWebApp/Components/CatalogsGrid.razor.css

@@ -0,0 +1,3 @@
+.catalog-edit-popup {
+    min-width: 720px;
+}

DbFirst.BlazorWebApp/Components/Layout/NavMenu.razor

@@ -31,6 +31,12 @@
                 <span class="bi bi-table-nav-menu" aria-hidden="true"></span> MassData
             </NavLink>
         </div>
+
+        <div class="nav-item px-3">
+            <NavLink class="nav-link" href="clock">
+                <span class="bi bi-clock-nav-menu" aria-hidden="true"></span> Clock
+            </NavLink>
+        </div>
     </nav>
 </div>
 

DbFirst.BlazorWebApp/Components/MassDataGrid.razor

@@ -1,68 +1,5 @@
-@using System.Text.Json
-@using Microsoft.AspNetCore.Components
-@using Microsoft.AspNetCore.Components.Rendering
-@using Microsoft.AspNetCore.Components.Forms
-@using DevExpress.Blazor
-@using DevExpress.Data.Filtering
 @inject MassDataApiClient Api
-@inject LayoutApiClient LayoutApi
-@inject IJSRuntime JsRuntime
-
-<style>
-    .action-panel { margin-bottom: 16px; }
-    .grid-section { margin-top: 12px; }
-    .pager-container {
-        display: flex;
-        justify-content: center;
-        margin-top: 12px;
-        margin-bottom: 16px;
-    }
-    .page-size-selector {
-        display: flex;
-        align-items: center;
-        gap: 8px;
-        flex-wrap: nowrap;
-    }
-    .page-size-label {
-        white-space: nowrap;
-    }
-    .page-size-combo {
-        width: 13ch;
-        min-width: 13ch;
-        max-width: 13ch;
-    }
-    .page-size-combo input {
-        text-align: left;
-    }
-    .massdata-edit-popup {
-        min-width: 720px;
-    }
-    .band-editor {
-        display: grid;
-        gap: 12px;
-        margin-bottom: 16px;
-    }
-    .band-controls {
-        display: flex;
-        flex-wrap: wrap;
-        gap: 8px;
-        align-items: center;
-    }
-    .band-row {
-        display: flex;
-        gap: 8px;
-        align-items: center;
-    }
-    .band-columns {
-        max-width: 720px;
-    }
-    .loading-container {
-        min-height: 160px;
-        display: flex;
-        align-items: center;
-        justify-content: center;
-    }
-</style>
+@inject BandLayoutService BandLayoutService
 
 @if (!string.IsNullOrWhiteSpace(errorMessage))
 {
@@ -87,6 +24,46 @@ else if (items.Count == 0)
 }
 else
 {
+    
+    <div class="band-editor">
+        <button class="band-editor-toggle" @onclick="() => bandEditorExpanded = !bandEditorExpanded">
+            <span class="band-editor-toggle-icon @(bandEditorExpanded ? "expanded" : "")">&#9658;</span>
+            <span>Layout</span>
+        </button>
+        @if (bandEditorExpanded)
+        {
+            <div class="band-editor-body">
+                <div class="band-controls">
+                    <DxButton Text="Band hinzufügen" Click="AddBand" />
+                    <DxButton Text="Layout speichern" Click="SaveLayoutAsync" Enabled="@CanSaveBandLayout" />
+                    <DxButton Text="Layout zurücksetzen" Click="ResetLayoutAsync" />
+                </div>
+                @foreach (var band in bandLayout.Bands)
+                {
+                    <div class="band-row">
+                        <DxTextBox Text="@band.Caption" TextChanged="@(value => UpdateBandCaption(band, value))" />
+                        <DxButton Text="Entfernen" Click="@(() => RemoveBand(band))" />
+                    </div>
+                }
+                <DxFormLayout CssClass="band-columns" ColCount="2">
+                    @foreach (var column in columnDefinitions)
+                    {
+                        <DxFormLayoutItem Caption="@column.Caption">
+                            <DxComboBox Data="@bandOptions"
+                                        TData="BandOption"
+                                        TValue="string"
+                                        TextFieldName="Caption"
+                                        ValueFieldName="Id"
+                                        Value="@GetColumnBand(column.FieldName)"
+                                        ValueChanged="@(value => UpdateColumnBand(column.FieldName, value))"
+                                        Width="100%" />
+                        </DxFormLayoutItem>
+                    }
+                </DxFormLayout>
+            </div>
+        }
+    </div>
+
     <div class="mb-3 page-size-selector">
         <span class="page-size-label">Datensätze je Seite:</span>
         <DxComboBox Data="@pageSizeOptions"
@@ -99,40 +76,11 @@ else
                     CssClass="page-size-combo" />
     </div>
 
-    <div class="band-editor">
-        <div class="band-controls">
-            <DxButton Text="Band hinzufügen" Click="AddBand" />
-            <DxButton Text="Layout speichern" Click="SaveLayoutAsync" Enabled="@CanSaveBandLayout" />
-            <DxButton Text="Band-Layout zurücksetzen" Click="ResetBandLayoutAsync" />
-        </div>
-        @foreach (var band in bandLayout.Bands)
-        {
-            <div class="band-row">
-                <DxTextBox Text="@band.Caption" TextChanged="@(value => UpdateBandCaption(band, value))" />
-                <DxButton Text="Entfernen" Click="@(() => RemoveBand(band))" />
-            </div>
-        }
-        <DxFormLayout CssClass="band-columns" ColCount="2">
-            @foreach (var column in columnDefinitions)
-            {
-                <DxFormLayoutItem Caption="@column.Caption">
-                    <DxComboBox Data="@bandOptions"
-                                TData="BandOption"
-                                TValue="string"
-                                TextFieldName="Caption"
-                                ValueFieldName="Id"
-                                Value="@GetColumnBand(column.FieldName)"
-                                ValueChanged="@(value => UpdateColumnBand(column.FieldName, value))"
-                                Width="100%" />
-                </DxFormLayoutItem>
-            }
-        </DxFormLayout>
-    </div>
-
     <div class="grid-section">
         <DxGrid Data="@items"
                 TItem="MassDataReadDto"
                 KeyFieldName="@nameof(MassDataReadDto.Id)"
+                SizeMode="@_sizeMode"
                 ShowGroupPanel="true"
                 ShowGroupedColumns="true"
                 AllowGroup="true"
@@ -151,11 +99,32 @@ else
                 FocusedRowEnabled="true"
                 @bind-FocusedRowKey="focusedRowKey"
                 @ref="gridRef">
+            <ToolbarTemplate>
+                <DxToolbar>
+                    <DxToolbarItem Alignment="ToolbarItemAlignment.Right">
+                        <Template Context="_">
+                            <DxDropDownButton Text="@FormatSizeText(_sizeMode)"
+                                              RenderStyle="ButtonRenderStyle.Secondary"
+                                              RenderStyleMode="ButtonRenderStyleMode.Text"
+                                              ItemClick="OnSizeChange">
+                                <Items>
+                                    @foreach (var size in _sizeModes)
+                                    {
+                                        <DxDropDownButtonItem Text="@FormatSizeText(size)" Id="@size.ToString()" />
+                                    }
+                                </Items>
+                            </DxDropDownButton>
+                        </Template>
+                    </DxToolbarItem>
+                </DxToolbar>
+            </ToolbarTemplate>
             <Columns>
                 @RenderColumns()
             </Columns>
             <EditFormTemplate Context="editFormContext">
-                @{ SetEditContext(editFormContext.EditContext); var editModel = (MassDataEditModel)editFormContext.EditModel; SetPopupHeaderText(editModel.IsNew); }
+                @{
+                    SetEditContext(editFormContext.EditContext); var editModel = (MassDataEditModel)editFormContext.EditModel; SetPopupHeaderText(editModel.IsNew);
+                }
                 <DxFormLayout ColCount="2">
                     <DxFormLayoutItem Caption="CustomerName">
                         <DxTextBox @bind-Text="editModel.CustomerName" Width="100%" />
@@ -213,13 +182,14 @@ else
     private int? focusedRowKey;
     private const string LayoutType = "GRID_BANDS";
     private const string LayoutKey = "MassDataGrid";
-    private const string LayoutUserStorageKey = "layoutUser";
     private string? layoutUser;
     private BandLayout bandLayout = new();
     private Dictionary<string, string> columnBandAssignments = new();
     private List<BandOption> bandOptions = new();
     private Dictionary<string, ColumnDefinition> columnLookup = new();
-    private readonly JsonSerializerOptions jsonOptions = new(JsonSerializerDefaults.Web);
+    private bool gridLayoutApplied;
+    private bool bandEditorExpanded;
+
     private List<ColumnDefinition> columnDefinitions = new()
     {
         new() { FieldName = nameof(MassDataReadDto.Id), Caption = "Id", Width = "90px", ReadOnly = true, FilterType = ColumnFilterType.Text },
@@ -231,15 +201,13 @@ else
         new() { FieldName = nameof(MassDataReadDto.ChangedWhen), Caption = "Changed", ReadOnly = true, FilterType = ColumnFilterType.Date }
     };
 
-    private bool CanSaveBandLayout => !string.IsNullOrWhiteSpace(layoutUser);
-
     private readonly List<PageSizeOption> pageSizeOptions = new()
     {
-        new() { Value = 100, Text = "100" },
-        new() { Value = 1000, Text = "1.000" },
-        new() { Value = 10000, Text = "10.000" },
+        new() { Value = 100,    Text = "100" },
+        new() { Value = 1000,   Text = "1.000" },
+        new() { Value = 10000,  Text = "10.000" },
         new() { Value = 100000, Text = "100.000" },
-        new() { Value = null, Text = "Alle" }
+        new() { Value = null,   Text = "Alle" }
     };
 
     private readonly List<ProcedureOption> procedureOptions = new()
@@ -247,16 +215,46 @@ else
         new() { Value = 0, Text = "PRMassdata_UpsertByCustomerName" }
     };
 
-    private bool gridLayoutApplied;
+    private bool CanSaveBandLayout => !string.IsNullOrWhiteSpace(layoutUser);
+
+    private SizeMode _sizeMode = SizeMode.Medium;
+    private static readonly List<SizeMode> _sizeModes = Enum.GetValues<SizeMode>().ToList();
+
+    private string FormatSizeText(SizeMode size) => size switch
+    {
+        SizeMode.Small => "Klein",
+        SizeMode.Medium => "Mittel",
+        SizeMode.Large => "Groß",
+        _ => size.ToString()
+    };
+
+    private void OnSizeChange(DropDownButtonItemClickEventArgs args)
+    {
+        _sizeMode = Enum.Parse<SizeMode>(args.ItemInfo.Id);
+    }
 
     protected override async Task OnInitializedAsync()
     {
-        columnLookup = columnDefinitions.ToDictionary(column => column.FieldName, StringComparer.OrdinalIgnoreCase);
-        await EnsureLayoutUserAsync();
-        await LoadBandLayoutAsync();
+        columnLookup = columnDefinitions.ToDictionary(c => c.FieldName, StringComparer.OrdinalIgnoreCase);
+        layoutUser = await BandLayoutService.EnsureLayoutUserAsync();
+        bandLayout = await BandLayoutService.LoadBandLayoutAsync(LayoutType, LayoutKey, layoutUser, columnLookup);
+        columnBandAssignments = BandLayoutService.BuildAssignmentsFromLayout(bandLayout);
+        ApplyColumnLayoutFromStorage();
+        _sizeMode = bandLayout.SizeMode;
+        UpdateBandOptions();
         await LoadPage(0);
     }
 
+    protected override async Task OnAfterRenderAsync(bool firstRender)
+    {
+        if (!gridLayoutApplied && gridRef != null && bandLayout.GridLayout != null)
+        {
+            gridRef.LoadLayout(bandLayout.GridLayout);
+            gridLayoutApplied = true;
+            await InvokeAsync(StateHasChanged);
+        }
+    }
+
     private async Task LoadPage(int page)
     {
         isLoading = true;
@@ -267,7 +265,6 @@ else
             var effectivePageSize = pageSize ?? (total == 0 ? 1 : total);
             pageCount = Math.Max(1, (int)Math.Ceiling(total / (double)effectivePageSize));
             pageIndex = Math.Clamp(page, 0, pageCount - 1);
-
             var skip = pageSize.HasValue ? pageIndex * pageSize.Value : 0;
             items = await Api.GetAllAsync(skip, pageSize);
         }
@@ -283,10 +280,7 @@ else
         }
     }
 
-    private async Task OnPageChanged(int index)
-    {
-        await LoadPage(index);
-    }
+    private async Task OnPageChanged(int index) => await LoadPage(index);
 
     private async Task OnPageSizeChanged(int? size)
     {
@@ -294,60 +288,14 @@ else
         await LoadPage(0);
     }
 
-    private async Task EnsureLayoutUserAsync()
-    {
-        layoutUser = await JsRuntime.InvokeAsync<string?>("localStorage.getItem", LayoutUserStorageKey);
-        if (string.IsNullOrWhiteSpace(layoutUser))
-        {
-            layoutUser = Guid.NewGuid().ToString("N");
-            await JsRuntime.InvokeVoidAsync("localStorage.setItem", LayoutUserStorageKey, layoutUser);
-        }
-    }
-
-    private async Task LoadBandLayoutAsync()
-    {
-        if (string.IsNullOrWhiteSpace(layoutUser))
-        {
-            bandLayout = new BandLayout();
-            UpdateBandOptions();
-            return;
-        }
-
-        var stored = await LayoutApi.GetAsync(LayoutType, LayoutKey, layoutUser);
-        if (stored != null && !string.IsNullOrWhiteSpace(stored.LayoutData))
-        {
-            var parsed = JsonSerializer.Deserialize<BandLayout>(stored.LayoutData, jsonOptions);
-            bandLayout = NormalizeBandLayout(parsed);
-        }
-        else
-        {
-            bandLayout = new BandLayout();
-        }
-
-        columnBandAssignments = BuildAssignmentsFromLayout(bandLayout);
-        ApplyColumnLayoutFromStorage();
-        UpdateBandOptions();
-    }
-
     private async Task SaveLayoutAsync()
     {
         if (string.IsNullOrWhiteSpace(layoutUser))
-        {
             return;
-        }
-
         try
         {
             CaptureColumnLayoutFromGrid();
-
-            var layoutData = JsonSerializer.Serialize(bandLayout, jsonOptions);
-            await LayoutApi.UpsertAsync(new LayoutDto
-            {
-                LayoutType = LayoutType,
-                LayoutKey = LayoutKey,
-                UserName = layoutUser,
-                LayoutData = layoutData
-            });
+            await BandLayoutService.SaveBandLayoutAsync(LayoutType, LayoutKey, layoutUser, bandLayout);
             infoMessage = "Layout gespeichert.";
             errorMessage = null;
         }
@@ -357,42 +305,39 @@ else
         }
     }
 
-    private void CaptureColumnLayoutFromGrid()
-    {
-        if (gridRef == null)
-        {
-            return;
-        }
-
-        var layout = gridRef.SaveLayout();
-        bandLayout.GridLayout = layout;
-
-        var orderedColumns = layout.Columns
-            .Where(column => !string.IsNullOrWhiteSpace(column.FieldName))
-            .OrderBy(column => column.VisibleIndex)
-            .ToList();
-
-        bandLayout.ColumnOrder = orderedColumns
-            .Select(column => column.FieldName)
-            .ToList();
-
-        bandLayout.ColumnWidths = orderedColumns
-            .Where(column => !string.IsNullOrWhiteSpace(column.Width))
-            .ToDictionary(column => column.FieldName, column => column.Width, StringComparer.OrdinalIgnoreCase);
-    }
-
-    private async Task ResetBandLayoutAsync()
+    private async Task ResetLayoutAsync()
     {
         if (string.IsNullOrWhiteSpace(layoutUser))
-        {
             return;
-        }
-
-        await LayoutApi.DeleteAsync(LayoutType, LayoutKey, layoutUser);
+        await BandLayoutService.ResetBandLayoutAsync(LayoutType, LayoutKey, layoutUser);
         bandLayout = new BandLayout();
         columnBandAssignments.Clear();
         UpdateBandOptions();
-        infoMessage = "Band-Layout zurückgesetzt.";
+        foreach (var column in columnDefinitions)
+            column.Width = null;
+        columnLookup = columnDefinitions.ToDictionary(c => c.FieldName, StringComparer.OrdinalIgnoreCase);
+        _sizeMode = SizeMode.Medium;
+        if (gridRef != null)
+            gridRef.LoadLayout(new GridPersistentLayout());
+        gridLayoutApplied = false;
+        infoMessage = "Layout zurückgesetzt.";
+        errorMessage = null;
+    }
+
+    private void CaptureColumnLayoutFromGrid()
+    {
+        if (gridRef == null) return;
+        var layout = gridRef.SaveLayout();
+        bandLayout.GridLayout = layout;
+        bandLayout.SizeMode = _sizeMode;
+        var orderedColumns = layout.Columns
+            .Where(c => !string.IsNullOrWhiteSpace(c.FieldName))
+            .OrderBy(c => c.VisibleIndex)
+            .ToList();
+        bandLayout.ColumnOrder = orderedColumns.Select(c => c.FieldName).ToList();
+        bandLayout.ColumnWidths = orderedColumns
+            .Where(c => !string.IsNullOrWhiteSpace(c.Width))
+            .ToDictionary(c => c.FieldName, c => c.Width, StringComparer.OrdinalIgnoreCase);
     }
 
     private void ApplyColumnLayoutFromStorage()
@@ -400,34 +345,22 @@ else
         foreach (var column in columnDefinitions)
         {
             if (bandLayout.ColumnWidths.TryGetValue(column.FieldName, out var width) && !string.IsNullOrWhiteSpace(width))
-            {
                 column.Width = width;
-            }
         }
-
-        columnLookup = columnDefinitions.ToDictionary(column => column.FieldName, StringComparer.OrdinalIgnoreCase);
+        columnLookup = columnDefinitions.ToDictionary(c => c.FieldName, StringComparer.OrdinalIgnoreCase);
     }
 
     private void AddBand()
     {
-        bandLayout.Bands.Add(new BandDefinition
-        {
-            Id = Guid.NewGuid().ToString("N"),
-            Caption = "Band"
-        });
+        bandLayout.Bands.Add(new BandDefinition { Id = Guid.NewGuid().ToString("N"), Caption = "Band" });
         UpdateBandOptions();
     }
 
     private void RemoveBand(BandDefinition band)
     {
         bandLayout.Bands.Remove(band);
-        var removedColumns = columnBandAssignments.Where(pair => pair.Value == band.Id)
-            .Select(pair => pair.Key)
-            .ToList();
-        foreach (var column in removedColumns)
-        {
-            columnBandAssignments.Remove(column);
-        }
+        foreach (var key in columnBandAssignments.Where(p => p.Value == band.Id).Select(p => p.Key).ToList())
+            columnBandAssignments.Remove(key);
         UpdateBandOptions();
         SyncBandsFromAssignments();
     }
@@ -441,77 +374,31 @@ else
     private void UpdateColumnBand(string fieldName, string? bandId)
     {
         if (string.IsNullOrWhiteSpace(bandId))
-        {
             columnBandAssignments.Remove(fieldName);
-        }
         else
-        {
             columnBandAssignments[fieldName] = bandId;
-        }
-
         SyncBandsFromAssignments();
     }
 
     private string GetColumnBand(string fieldName)
-    {
-        return columnBandAssignments.TryGetValue(fieldName, out var bandId) ? bandId : string.Empty;
-    }
+        => columnBandAssignments.TryGetValue(fieldName, out var bandId) ? bandId : string.Empty;
 
     private void SyncBandsFromAssignments()
     {
         foreach (var band in bandLayout.Bands)
         {
             band.Columns = columnDefinitions
-                .Where(column => columnBandAssignments.TryGetValue(column.FieldName, out var bandId) && bandId == band.Id)
-                .Select(column => column.FieldName)
+                .Where(c => columnBandAssignments.TryGetValue(c.FieldName, out var id) && id == band.Id)
+                .Select(c => c.FieldName)
                 .ToList();
         }
-
         StateHasChanged();
     }
 
     private void UpdateBandOptions()
     {
         bandOptions = new List<BandOption> { new() { Id = string.Empty, Caption = "Ohne Band" } };
-        bandOptions.AddRange(bandLayout.Bands.Select(band => new BandOption { Id = band.Id, Caption = band.Caption }));
-    }
-
-    private Dictionary<string, string> BuildAssignmentsFromLayout(BandLayout layout)
-    {
-        var assignments = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-        foreach (var band in layout.Bands)
-        {
-            foreach (var column in band.Columns)
-            {
-                assignments[column] = band.Id;
-            }
-        }
-
-        return assignments;
-    }
-
-    private BandLayout NormalizeBandLayout(BandLayout? layout)
-    {
-        layout ??= new BandLayout();
-        layout.Bands ??= new List<BandDefinition>();
-        layout.ColumnOrder ??= new List<string>();
-        layout.ColumnWidths ??= new Dictionary<string, string?>(StringComparer.OrdinalIgnoreCase);
-        foreach (var band in layout.Bands)
-        {
-            if (string.IsNullOrWhiteSpace(band.Id))
-            {
-                band.Id = Guid.NewGuid().ToString("N");
-            }
-
-            if (string.IsNullOrWhiteSpace(band.Caption))
-            {
-                band.Caption = "Band";
-            }
-
-            band.Columns = band.Columns?.Where(columnLookup.ContainsKey).ToList() ?? new List<string>();
-        }
-
-        return layout;
+        bandOptions.AddRange(bandLayout.Bands.Select(b => new BandOption { Id = b.Id, Caption = b.Caption }));
     }
 
     private RenderFragment RenderColumns() => builder =>
@@ -520,20 +407,12 @@ else
         builder.OpenComponent<DxGridCommandColumn>(seq++);
         builder.AddAttribute(seq++, "Width", "120px");
         builder.CloseComponent();
-
-        var grouped = bandLayout.Bands.SelectMany(band => band.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
-        foreach (var column in columnDefinitions.Where(column => !grouped.Contains(column.FieldName)))
-        {
+        var grouped = bandLayout.Bands.SelectMany(b => b.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
+        foreach (var column in columnDefinitions.Where(c => !grouped.Contains(c.FieldName)))
             BuildDataColumn(builder, ref seq, column);
-        }
-
         foreach (var band in bandLayout.Bands)
         {
-            if (band.Columns.Count == 0)
-            {
-                continue;
-            }
-
+            if (band.Columns.Count == 0) continue;
             builder.OpenComponent<DxGridBandColumn>(seq++);
             builder.AddAttribute(seq++, "Caption", band.Caption);
             builder.AddAttribute(seq++, "Columns", (RenderFragment)(bandBuilder =>
@@ -542,9 +421,7 @@ else
                 foreach (var columnName in band.Columns)
                 {
                     if (columnLookup.TryGetValue(columnName, out var column))
-                    {
                         BuildDataColumn(bandBuilder, ref bandSeq, column);
-                    }
                 }
             }));
             builder.CloseComponent();
@@ -557,35 +434,19 @@ else
         builder.AddAttribute(seq++, "FieldName", column.FieldName);
         builder.AddAttribute(seq++, "Caption", column.Caption);
         if (!string.IsNullOrWhiteSpace(column.Width))
-        {
             builder.AddAttribute(seq++, "Width", column.Width);
-        }
-
         if (!string.IsNullOrWhiteSpace(column.DisplayFormat))
-        {
             builder.AddAttribute(seq++, "DisplayFormat", column.DisplayFormat);
-        }
-
         if (column.ReadOnly)
-        {
             builder.AddAttribute(seq++, "ReadOnly", true);
-        }
-
         builder.CloseComponent();
     }
 
     private void SetEditContext(EditContext context)
     {
-        if (editContext == context)
-        {
-            return;
-        }
-
+        if (editContext == context) return;
         if (editContext != null)
-        {
             editContext.OnFieldChanged -= OnEditFieldChanged;
-        }
-
         editContext = context;
         validationMessageStore = new ValidationMessageStore(editContext);
         editContext.OnFieldChanged += OnEditFieldChanged;
@@ -593,30 +454,21 @@ else
 
     private void OnEditFieldChanged(object? sender, FieldChangedEventArgs e)
     {
-        if (validationMessageStore == null || editContext == null)
-        {
-            return;
-        }
-
+        if (validationMessageStore == null || editContext == null) return;
         if (e.FieldIdentifier.FieldName == nameof(MassDataEditModel.UpdateProcedure))
         {
             validationMessageStore.Clear();
             editContext.NotifyValidationStateChanged();
             return;
         }
-
         if (e.FieldIdentifier.FieldName == nameof(MassDataEditModel.CustomerName))
         {
-            var field = new FieldIdentifier(editContext.Model, nameof(MassDataEditModel.CustomerName));
-            validationMessageStore.Clear(field);
+            validationMessageStore.Clear(new FieldIdentifier(editContext.Model, nameof(MassDataEditModel.CustomerName)));
             editContext.NotifyValidationStateChanged();
         }
     }
 
-    private void SetPopupHeaderText(bool isNew)
-    {
-        popupHeaderText = isNew ? "Neu" : "Edit";
-    }
+    private void SetPopupHeaderText(bool isNew) => popupHeaderText = isNew ? "Neu" : "Edit";
 
     private async Task OnCustomizeEditModel(GridCustomizeEditModelEventArgs e)
     {
@@ -626,7 +478,6 @@ else
             SetPopupHeaderText(true);
             return;
         }
-
         var item = (MassDataReadDto)e.DataItem;
         e.EditModel = new MassDataEditModel
         {
@@ -646,10 +497,8 @@ else
     {
         errorMessage = null;
         infoMessage = null;
-
         validationMessageStore?.Clear();
         editContext?.NotifyValidationStateChanged();
-
         var editModel = (MassDataEditModel)e.EditModel;
         if (!decimal.TryParse(editModel.AmountText, out var amount))
         {
@@ -657,7 +506,6 @@ else
             e.Cancel = true;
             return;
         }
-
         if (editModel.IsNew)
         {
             var existing = await Api.GetByCustomerNameAsync(editModel.CustomerName);
@@ -668,7 +516,6 @@ else
                 return;
             }
         }
-
         var dto = new MassDataWriteDto
         {
             CustomerName = editModel.CustomerName,
@@ -676,7 +523,6 @@ else
             Category = editModel.Category,
             StatusFlag = editModel.StatusFlag
         };
-
         try
         {
             var saved = await Api.UpsertAsync(dto);
@@ -693,13 +539,8 @@ else
 
     private void AddValidationError(MassDataEditModel editModel, string fieldName, string message)
     {
-        if (editContext == null || validationMessageStore == null)
-        {
-            return;
-        }
-
-        var field = new FieldIdentifier(editModel, fieldName);
-        validationMessageStore.Add(field, message);
+        if (editContext == null || validationMessageStore == null) return;
+        validationMessageStore.Add(new FieldIdentifier(editModel, fieldName), message);
         editContext.NotifyValidationStateChanged();
     }
 
@@ -710,44 +551,6 @@ else
         e.Cancel = true;
         return Task.CompletedTask;
     }
-    
-    private sealed class BandLayout
-    {
-        public List<BandDefinition> Bands { get; set; } = new();
-        public List<string> ColumnOrder { get; set; } = new();
-        public Dictionary<string, string?> ColumnWidths { get; set; } = new(StringComparer.OrdinalIgnoreCase);
-        public GridPersistentLayout? GridLayout { get; set; }
-    }
-
-    private sealed class BandDefinition
-    {
-        public string Id { get; set; } = string.Empty;
-        public string Caption { get; set; } = string.Empty;
-        public List<string> Columns { get; set; } = new();
-    }
-
-    private sealed class BandOption
-    {
-        public string Id { get; set; } = string.Empty;
-        public string Caption { get; set; } = string.Empty;
-    }
-
-    private sealed class ColumnDefinition
-    {
-        public string FieldName { get; init; } = string.Empty;
-        public string Caption { get; init; } = string.Empty;
-        public string? Width { get; set; }
-        public string? DisplayFormat { get; init; }
-        public bool ReadOnly { get; init; }
-        public ColumnFilterType FilterType { get; init; }
-    }
-
-    private enum ColumnFilterType
-    {
-        Text,
-        Bool,
-        Date
-    }
 
     private sealed class MassDataEditModel
     {
@@ -767,31 +570,9 @@ else
         public string Text { get; set; } = string.Empty;
     }
 
-    private sealed class BoolFilterOption
-    {
-        public bool? Value { get; set; }
-        public string Text { get; set; } = string.Empty;
-    }
-
     private sealed class PageSizeOption
     {
         public int? Value { get; set; }
         public string Text { get; set; } = string.Empty;
     }
-
-    private sealed class FilterOperatorOption
-    {
-        public string Value { get; set; } = string.Empty;
-        public string Text { get; set; } = string.Empty;
-    }
-
-    protected override async Task OnAfterRenderAsync(bool firstRender)
-    {
-        if (!gridLayoutApplied && gridRef != null && bandLayout.GridLayout != null)
-        {
-            gridRef.LoadLayout(bandLayout.GridLayout);
-            gridLayoutApplied = true;
-            await InvokeAsync(StateHasChanged);
-        }
-    }
-}
+}

DbFirst.BlazorWebApp/Components/MassDataGrid.razor.css

@@ -0,0 +1,3 @@
+.massdata-edit-popup {
+    min-width: 720px;
+}

DbFirst.BlazorWebApp/Components/Pages/Clock.razor

@@ -0,0 +1,100 @@
+@rendermode InteractiveServer
+@page "/clock"
+@inject TimeApiClient TimeApi
+@implements IAsyncDisposable
+
+<PageTitle>Clock</PageTitle>
+
+<h3>DB Server Clock</h3>
+
+<div class="clock-wrapper">
+    <div class="clock-display @(_error != null ? "clock-error" : "")">
+        @if (_dbTime.HasValue)
+        {
+            <span class="clock-time">@_dbTime.Value.ToString("HH:mm:ss")</span>
+            <span class="clock-date">@_dbTime.Value.ToString("dd.MM.yyyy")</span>
+        }
+        else if (_error != null)
+        {
+            <span class="clock-time">--:--:--</span>
+            <span class="clock-date text-danger">@_error</span>
+        }
+        else
+        {
+            <span class="clock-time">...</span>
+        }
+    </div>
+</div>
+
+<style>
+    .clock-wrapper {
+        display: flex;
+        justify-content: center;
+        align-items: center;
+        height: 40vh;
+    }
+
+    .clock-display {
+        display: flex;
+        flex-direction: column;
+        align-items: center;
+        background: var(--bs-body-bg, #1e1e2e);
+        border: 2px solid var(--bs-border-color, #444);
+        border-radius: 1rem;
+        padding: 2rem 4rem;
+        box-shadow: 0 4px 24px rgba(0,0,0,0.3);
+    }
+
+    .clock-time {
+        font-size: 5rem;
+        font-weight: 700;
+        font-variant-numeric: tabular-nums;
+        letter-spacing: 0.1em;
+        color: var(--bs-primary, #0d6efd);
+    }
+
+    .clock-date {
+        font-size: 1.4rem;
+        margin-top: 0.5rem;
+        opacity: 0.75;
+    }
+
+    .clock-error .clock-time {
+        color: var(--bs-danger, #dc3545);
+    }
+</style>
+
+@code {
+    private DateTime? _dbTime;
+    private string? _error;
+    private Timer? _timer;
+
+    protected override async Task OnInitializedAsync()
+    {
+        await TickAsync();
+        _timer = new Timer(async _ =>
+        {
+            await TickAsync();
+            await InvokeAsync(StateHasChanged);
+        }, null, TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(1));
+    }
+
+    private async Task TickAsync()
+    {
+        try
+        {
+            _dbTime = await TimeApi.InsertAndGetLastAsync();
+            _error = null;
+        }
+        catch (Exception ex)
+        {
+            _error = ex.Message;
+        }
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (_timer != null)
+            await _timer.DisposeAsync();
+    }
+}

DbFirst.BlazorWebApp/Components/Pages/Dashboard.razor

@@ -5,46 +5,6 @@
 @inject NavigationManager Navigation
 @inject DashboardApiClient DashboardApi
 
-<style>
-    .dashboard-shell {
-        display: flex;
-        gap: 0;
-        min-height: 800px;
-        border: 1px solid #e6e6e6;
-        border-radius: 6px;
-        overflow: hidden;
-        background: #fff;
-    }
-    .dashboard-nav {
-        width: 220px;
-        border-right: 1px solid #e6e6e6;
-        background: #fafafa;
-    }
-    .dashboard-nav-title {
-        padding: 0.75rem 1rem 0.5rem;
-        font-size: 0.7rem;
-        text-transform: uppercase;
-        letter-spacing: 0.08em;
-        color: #6c757d;
-        font-weight: 600;
-    }
-    .dashboard-nav-link {
-        display: block;
-        padding: 0.55rem 1rem;
-        color: inherit;
-        text-decoration: none;
-    }
-    .dashboard-nav-link.active {
-        background: #e9ecef;
-        font-weight: 600;
-    }
-    .dashboard-content {
-        flex: 1;
-        min-width: 0;
-        padding: 1rem;
-    }
-</style>
-
 <PageTitle>Dashboards</PageTitle>
 
 <div class="dashboard-shell">

DbFirst.BlazorWebApp/Components/Pages/Dashboard.razor.css

@@ -0,0 +1,42 @@
+.dashboard-shell {
+    display: flex;
+    gap: 0;
+    min-height: 800px;
+    border: 1px solid #e6e6e6;
+    border-radius: 6px;
+    overflow: hidden;
+    background: #fff;
+}
+
+.dashboard-nav {
+    width: 220px;
+    border-right: 1px solid #e6e6e6;
+    background: #fafafa;
+}
+
+.dashboard-nav-title {
+    padding: 0.75rem 1rem 0.5rem;
+    font-size: 0.7rem;
+    text-transform: uppercase;
+    letter-spacing: 0.08em;
+    color: #6c757d;
+    font-weight: 600;
+}
+
+.dashboard-nav-link {
+    display: block;
+    padding: 0.55rem 1rem;
+    color: inherit;
+    text-decoration: none;
+}
+
+    .dashboard-nav-link.active {
+        background: #e9ecef;
+        font-weight: 600;
+    }
+
+.dashboard-content {
+    flex: 1;
+    min-width: 0;
+    padding: 1rem;
+}

DbFirst.BlazorWebApp/Components/Pages/Home.razor

@@ -1,7 +1,43 @@
-@page "/"
+@rendermode InteractiveServer
+
+@page "/"
 
 <PageTitle>Home</PageTitle>
 
-<h1>Hello, world!</h1>
+<h1>Database first</h1>
 
-Welcome to your new app.
+<DxCarousel Width="100%"
+            Height="calc(100vh - 9rem)"
+            Data="@GetCarouselData()"
+            ImageSrcField="Source"
+            ImageAltField="AlternateText"
+            LoopNavigationEnabled="true"
+            SlideShowEnabled="true"
+            SlideShowDelay="3000"
+            PauseSlideShowOnHover="true"
+            ImageSizeMode="CarouselImageSizeMode.FitProportional">
+</DxCarousel>
+
+@code {
+    List<CarouselData> GetCarouselData()
+    {
+        return new List<CarouselData>
+        {
+            new CarouselData("/images/DbFirstBefehl.png", "DbFirstBefehl"),
+            new CarouselData("/images/CQRS - Katalog-Datenfluss.png", "CQRS - Katalog-Datenfluss"),
+            new CarouselData("/images/CQRS - Catalog Create, Update, Delete.png", "CQRS - Catalog Create, Update, Delete"),
+        };
+    }
+
+    public class CarouselData
+    {
+        public string Source { get; set; }
+        public string AlternateText { get; set; }
+
+        public CarouselData(string source, string alt)
+        {
+            Source = source;
+            AlternateText = alt;
+        }
+    }
+}

DbFirst.BlazorWebApp/Components/_Imports.razor

@@ -1,6 +1,8 @@
 @using System.Net.Http
 @using System.Net.Http.Json
+@using System.Text.Json
 @using Microsoft.AspNetCore.Components.Forms
+@using Microsoft.AspNetCore.Components.Rendering
 @using Microsoft.AspNetCore.Components.Routing
 @using Microsoft.AspNetCore.Components.Web
 @using static Microsoft.AspNetCore.Components.Web.RenderMode
@@ -10,8 +12,9 @@
 @using DbFirst.BlazorWebApp
 @using DbFirst.BlazorWebApp.Components
 @using DbFirst.BlazorWebApp.Models
+@using DbFirst.BlazorWebApp.Models.Grid
 @using DbFirst.BlazorWebApp.Services
 @using DevExpress.Blazor
 @using DevExpress.DashboardBlazor
 @using DevExpress.DashboardWeb
-@using DbFirst.BlazorWebApp
+@using DevExpress.Data.Filtering

DbFirst.BlazorWebApp/DbFirst.BlazorWebApp.csproj

@@ -11,10 +11,11 @@
     <PackageReference Include="DevExpress.Blazor.Dashboard" Version="25.2.3" />
     <PackageReference Include="DevExpress.Blazor.Themes" Version="25.2.3" />
     <PackageReference Include="DevExpress.Blazor.Themes.Fluent" Version="25.2.3" />
-  </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="DevExpress.Blazor" Version="25.2.3" />
     <PackageReference Include="Microsoft.AspNetCore.SignalR.Client" Version="8.0.22" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Folder Include="wwwroot\images\" />
+  </ItemGroup>
+
 </Project>

DbFirst.BlazorWebApp/Models/Grid/BandLayoutModels.cs

@@ -0,0 +1,43 @@
+using DevExpress.Blazor;
+
+namespace DbFirst.BlazorWebApp.Models.Grid
+{
+    public class BandLayout
+    {
+        public List<BandDefinition> Bands { get; set; } = new();
+        public List<string> ColumnOrder { get; set; } = new();
+        public Dictionary<string, string?> ColumnWidths { get; set; } = new(StringComparer.OrdinalIgnoreCase);
+        public GridPersistentLayout? GridLayout { get; set; }
+        public SizeMode SizeMode { get; set; } = SizeMode.Medium;
+    }
+
+    public class BandDefinition
+    {
+        public string Id { get; set; } = string.Empty;
+        public string Caption { get; set; } = string.Empty;
+        public List<string> Columns { get; set; } = new();
+    }
+
+    public class BandOption
+    {
+        public string Id { get; set; } = string.Empty;
+        public string Caption { get; set; } = string.Empty;
+    }
+
+    public class ColumnDefinition
+    {
+        public string FieldName { get; init; } = string.Empty;
+        public string Caption { get; init; } = string.Empty;
+        public string? Width { get; set; }
+        public string? DisplayFormat { get; init; }
+        public bool ReadOnly { get; init; }
+        public ColumnFilterType FilterType { get; init; }
+    }
+
+    public enum ColumnFilterType
+    {
+        Text,
+        Bool,
+        Date
+    }
+}

DbFirst.BlazorWebApp/Program.cs

@@ -10,6 +10,7 @@ builder.Services.AddRazorComponents()
 
 builder.Services.AddDevExpressBlazor(options => options.BootstrapVersion = BootstrapVersion.v5);
 builder.Services.AddScoped<ThemeState>();
+builder.Services.AddScoped<BandLayoutService>();
 
 var apiBaseUrl = builder.Configuration["ApiBaseUrl"];
 if (!string.IsNullOrWhiteSpace(apiBaseUrl))
@@ -30,6 +31,10 @@ if (!string.IsNullOrWhiteSpace(apiBaseUrl))
     {
         client.BaseAddress = new Uri(apiBaseUrl);
     });
+    builder.Services.AddHttpClient<TimeApiClient>(client =>
+    {
+        client.BaseAddress = new Uri(apiBaseUrl);
+    });
 }
 else
 {
@@ -37,6 +42,7 @@ else
     builder.Services.AddHttpClient<DashboardApiClient>();
     builder.Services.AddHttpClient<MassDataApiClient>();
     builder.Services.AddHttpClient<LayoutApiClient>();
+    builder.Services.AddHttpClient<TimeApiClient>();
 }
 
 var app = builder.Build();

DbFirst.BlazorWebApp/Services/BandLayoutService.cs

@@ -0,0 +1,103 @@
+using DbFirst.BlazorWebApp.Models;
+using DbFirst.BlazorWebApp.Models.Grid;
+using Microsoft.JSInterop;
+using System.Text.Json;
+
+namespace DbFirst.BlazorWebApp.Services
+{
+    public class BandLayoutService(LayoutApiClient layoutApi, IJSRuntime jsRuntime)
+    {
+        private const string LayoutUserStorageKey = "layoutUser";
+        private readonly JsonSerializerOptions _jsonOptions = new(JsonSerializerDefaults.Web);
+
+        public async Task<string> EnsureLayoutUserAsync()
+        {
+            var layoutUser = await jsRuntime.InvokeAsync<string?>("localStorage.getItem", LayoutUserStorageKey);
+            if (string.IsNullOrWhiteSpace(layoutUser))
+            {
+                layoutUser = Guid.NewGuid().ToString("N");
+                await jsRuntime.InvokeVoidAsync("localStorage.setItem", LayoutUserStorageKey, layoutUser);
+            }
+            return layoutUser;
+        }
+
+        public async Task<BandLayout> LoadBandLayoutAsync(
+            string layoutType,
+            string layoutKey,
+            string layoutUser,
+            Dictionary<string, ColumnDefinition> columnLookup)
+        {
+            if (string.IsNullOrWhiteSpace(layoutUser))
+                return new BandLayout();
+
+            var stored = await layoutApi.GetAsync(layoutType, layoutKey, layoutUser);
+            if (stored != null && !string.IsNullOrWhiteSpace(stored.LayoutData))
+            {
+                var parsed = JsonSerializer.Deserialize<BandLayout>(stored.LayoutData, _jsonOptions);
+                return NormalizeBandLayout(parsed, columnLookup);
+            }
+
+            return new BandLayout();
+        }
+
+        public async Task SaveBandLayoutAsync(
+            string layoutType,
+            string layoutKey,
+            string layoutUser,
+            BandLayout bandLayout)
+        {
+            var layoutData = JsonSerializer.Serialize(bandLayout, _jsonOptions);
+            await layoutApi.UpsertAsync(new LayoutDto
+            {
+                LayoutType = layoutType,
+                LayoutKey = layoutKey,
+                UserName = layoutUser,
+                LayoutData = layoutData
+            });
+        }
+
+        public async Task ResetBandLayoutAsync(
+            string layoutType,
+            string layoutKey,
+            string layoutUser)
+        {
+            await layoutApi.DeleteAsync(layoutType, layoutKey, layoutUser);
+        }
+
+        public Dictionary<string, string> BuildAssignmentsFromLayout(BandLayout layout)
+        {
+            var assignments = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+            foreach (var band in layout.Bands)
+            {
+                foreach (var column in band.Columns)
+                {
+                    assignments[column] = band.Id;
+                }
+            }
+            return assignments;
+        }
+
+        public BandLayout NormalizeBandLayout(
+            BandLayout? layout,
+            Dictionary<string, ColumnDefinition> columnLookup)
+        {
+            layout ??= new BandLayout();
+            layout.Bands ??= new List<BandDefinition>();
+            layout.ColumnOrder ??= new List<string>();
+            layout.ColumnWidths ??= new Dictionary<string, string?>(StringComparer.OrdinalIgnoreCase);
+
+            foreach (var band in layout.Bands)
+            {
+                if (string.IsNullOrWhiteSpace(band.Id))
+                    band.Id = Guid.NewGuid().ToString("N");
+
+                if (string.IsNullOrWhiteSpace(band.Caption))
+                    band.Caption = "Band";
+
+                band.Columns = band.Columns?.Where(columnLookup.ContainsKey).ToList() ?? new List<string>();
+            }
+
+            return layout;
+        }
+    }
+}

DbFirst.BlazorWebApp/Services/TimeApiClient.cs

@@ -0,0 +1,27 @@
+using System.Net.Http.Json;
+
+namespace DbFirst.BlazorWebApp.Services;
+
+public class TimeApiClient
+{
+    private readonly HttpClient _httpClient;
+    private const string Endpoint = "api/time";
+
+    public TimeApiClient(HttpClient httpClient)
+    {
+        _httpClient = httpClient;
+    }
+
+    public async Task<DateTime?> InsertAndGetLastAsync()
+    {
+        var response = await _httpClient.PostAsync(Endpoint, null);
+        response.EnsureSuccessStatusCode();
+        var result = await response.Content.ReadFromJsonAsync<TimeResponse>();
+        return result?.Now;
+    }
+
+    private sealed class TimeResponse
+    {
+        public DateTime? Now { get; set; }
+    }
+}

DbFirst.BlazorWebApp/wwwroot/app.css

@@ -1,10 +1,27 @@
+:root {
+    --global-size: 16px;
+}
+
 html, body {
     font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
+    font-size: var(--global-size);
+}
+
+/* Theme-Variablen */
+.app-light {
+    --band-editor-bg: #f8f9fa;
+    --band-editor-border: #dee2e6;
+    --band-toggle-hover-bg: #e9ecef;
+    --grid-stripe-bg: rgba(0, 0, 0, 0.03);
 }
 
 .app-dark {
     background-color: #1b1b1b;
     color: #f1f1f1;
+    --band-editor-bg: #2d2d2d;
+    --band-editor-border: #444444;
+    --band-toggle-hover-bg: #3a3a3a;
+    --grid-stripe-bg: rgba(255, 255, 255, 0.04);
 }
 
 a, .btn-link {
@@ -22,7 +39,7 @@ a, .btn-link {
 }
 
 .btn:focus, .btn:active:focus, .btn-link.nav-link:focus, .form-control:focus, .form-check-input:focus {
-  box-shadow: 0 0 0 0.1rem white, 0 0 0 0.25rem #258cfb;
+    box-shadow: 0 0 0 0.1rem white, 0 0 0 0.25rem #258cfb;
 }
 
 .content {
@@ -46,7 +63,7 @@ h1:focus {
 }
 
 .blazor-error-boundary {
-    background: url(data:image/svg+xml;base64,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) no-repeat 1rem/1.8rem, #b32121;
+    background: url(data:image/svg+xml;base64,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) no-repeat 1rem/1.8rem, #b32121;
     padding: 1rem 1rem 1rem 3.7rem;
     color: white;
 }
@@ -58,3 +75,113 @@ h1:focus {
 .darker-border-checkbox.form-check-input {
     border-color: #929292;
 }
+
+/* Grid Band-Editor */
+.band-editor {
+    margin-top: 4px;
+    margin-bottom: 16px;
+    border: 1px solid var(--band-editor-border);
+    border-radius: 4px;
+    background-color: var(--band-editor-bg);
+    overflow: hidden;
+}
+
+.band-editor-toggle {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    width: 100%;
+    padding: 8px 12px;
+    background: none;
+    border: none;
+    cursor: pointer;
+    font-size: inherit;
+    color: inherit;
+    text-align: left;
+}
+
+    .band-editor-toggle:hover {
+        background-color: var(--band-toggle-hover-bg);
+    }
+
+.band-editor-toggle-icon {
+    font-size: 0.7rem;
+    transition: transform 0.2s ease;
+    display: inline-block;
+}
+
+    .band-editor-toggle-icon.expanded {
+        transform: rotate(90deg);
+    }
+
+.band-editor-body {
+    display: flex;
+    flex-direction: column;
+    gap: 12px;
+    padding: 0 12px 12px 12px;
+}
+
+.band-controls {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 8px;
+    align-items: center;
+}
+
+.band-row {
+    display: flex;
+    gap: 8px;
+    align-items: center;
+}
+
+.band-columns {
+    max-width: 720px;
+    margin-top: 4px;
+}
+
+.grid-section {
+    margin-top: 4px;
+}
+
+/* Grid Zebra-Striping */
+dxbl-grid tbody tr:nth-child(even) td {
+    background-color: var(--grid-stripe-bg) !important;
+}
+
+/* MassData-spezifisch */
+.page-size-selector {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    flex-wrap: nowrap;
+    margin-bottom: 12px;
+}
+
+.page-size-label {
+    white-space: nowrap;
+}
+
+.page-size-combo {
+    width: 13ch;
+    min-width: 13ch;
+    max-width: 13ch;
+}
+
+    .page-size-combo input {
+        text-align: left;
+    }
+
+.pager-container {
+    display: flex;
+    justify-content: center;
+    margin-top: 12px;
+    margin-bottom: 16px;
+}
+
+/* Lade-Spinner */
+.loading-container {
+    min-height: 160px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+}

DbFirst.BlazorWebApp/wwwroot/js/size-manager.js

@@ -0,0 +1,3 @@
+window.setSize = function (fontSize) {
+    document.documentElement.style.setProperty('--global-size', fontSize);
+};

DbFirst.Domain/Entities/Time.cs

@@ -0,0 +1,6 @@
+namespace DbFirst.Domain.Entities;
+
+public class TimeRecord
+{
+    public DateTime? Now { get; set; }
+}

DbFirst.Infrastructure/ApplicationDbContext.cs

@@ -16,6 +16,7 @@ public partial class ApplicationDbContext : DbContext
 
     public virtual DbSet<VwmyCatalog> VwmyCatalogs { get; set; }
     public virtual DbSet<SmfLayout> SmfLayouts { get; set; }
+    public virtual DbSet<TimeRecord> Times { get; set; }
 
     protected override void OnModelCreating(ModelBuilder modelBuilder)
     {
@@ -83,6 +84,16 @@ public partial class ApplicationDbContext : DbContext
                 .HasColumnName("CHANGED_WHEN");
         });
 
+        modelBuilder.Entity<TimeRecord>(entity =>
+        {
+            entity.HasNoKey();
+            entity.ToTable("TIME");
+
+            entity.Property(e => e.Now)
+                .HasColumnType("datetime")
+                .HasColumnName("NOW");
+        });
+
         OnModelCreatingPartial(modelBuilder);
     }
 

DbFirst.Infrastructure/Repositories/TimeRepository.cs

@@ -0,0 +1,28 @@
+using DbFirst.Application.Repositories;
+using DbFirst.Domain.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace DbFirst.Infrastructure.Repositories;
+
+public class TimeRepository : ITimeRepository
+{
+    private readonly ApplicationDbContext _db;
+
+    public TimeRepository(ApplicationDbContext db)
+    {
+        _db = db;
+    }
+
+    public async Task InsertAsync(CancellationToken cancellationToken = default)
+    {
+        await _db.Database.ExecuteSqlRawAsync("INSERT INTO [TIME] (NOW) VALUES (GETDATE())", cancellationToken);
+    }
+
+    public async Task<TimeRecord?> GetLastAsync(CancellationToken cancellationToken = default)
+    {
+        return await _db.Times
+            .AsNoTracking()
+            .OrderByDescending(t => t.Now)
+            .FirstOrDefaultAsync(cancellationToken);
+    }
+}